Not applicable.
Not applicable.
Not applicable.
This invention is directed to the temporary end-to-end alignment of two or more workpieces, such as tubing, pipe, handrail, fittings, shafts, or solid bar, to facilitate their permanent joining, by welding, brazing, soldering, adhesive application, or other physical or chemical means. This invention is intended to fulfill a long-felt need for an alignment device that is light, small, portable, interchangeable, easily maneuverable in confined spaces, and readily usable by pipefitters, millwrights, welders, plumbers, ironworkers, and other practitioners in the fabrication, construction, and repair trades, having a variety of skills and aptitudes.
In the fabrication, construction and repair trades, there has persisted a very real problem of pre-positioning and holding a pair of pipe sections together, prior to their joining by welding or other permanent attachment. The problem has been compounded for pipes, fittings, and other workpieces of non-circular cross-section, since the prior art has tended to focus on circular pipe. Pipe sections, tube sections, solid sections, and workpieces of other cross-sections can be quite heavy, and it can be difficult, under the best of circumstances, to align successive sections, to hold a connecting section in exact alignment with, and, in appropriate space relationship with, its prior section. This problem is exacerbated in tight work areas, such as buildings, and with vertical or near-vertical workpieces, such as stack pipes or poles. Small workpieces, at the other end of the spectrum, may be lighter to hold, but harder to handle, due to placement in confined areas, or areas partially or mostly inaccessible to the tradesperson. This situation is complicated when the tradesperson must align and/or attach pipe of varying outer diameters, having the same inner diameter. The situation is also complicated when the tradesperson must align and/or attach various forms of fittings, including, but not limited to, elbows, reducers, tees, crosses, caps, stubs, rings, flanges, and weldments.
Various attempts have been made over the years to address these problems. The earliest attempts used a combination of a C-shaped clamp, an angle iron, and a chain or chain clamp, to effect alignment. Later attempts, such as the devices covered by Hickey U.S. Pat. Nos. 1,848,527, and 1,940,910, issued, respectively, on Mar. 8, 1932 and Dec. 26, 1933, combined a rigid frame, a chain, and a rotatable handle, for restraint of adjacent pipe/pipe joints and adjacent pipe/fitting joints, respectively. However, the heavy, rigid frame and rotatable handle of the Hickey clamps require substantial working room and storage room.
Other attempts in the prior art include U.S. Pat. No. 3,192,804, granted to Peterson on Jul. 6, 1965, for a chain clamp utilizing a locking wrench, and U.S. Pat. No. 4,477,937, granted to Costello on Oct. 23rd, 1984, for a combination pliers, clamp, and wrench, but neither hand tool provides fittings for aligning successive workpieces.
Recent art for pipe alignment devices has evolved along two approaches, the first approach utilizing a rigid, lockable clamp, secured by a single arcuate movement at the perimeter of the pipe, the second approach utilizing a crank-tightened chain. Examples of the first, rigid approach include U.S. Pat. No. 2,846,968, issued to Tipton on Aug. 12, 1958; U.S. Pat. No. 3,422,519, issued to Fehlman on Jan. 21,1969; U.S. Pat. No. 3,467,295, issued to Watson on Sept. 16, 1969; and U.S. Pat. No. 3,952,936, issued to Dearman on Apr. 27th, 1976. The use of rigid clamps, however, is limited to a single size of circular pipe. Furthermore, such clamps have a tendency to be bulky and heavy, especially for larger pipe diameters.
Examples of the second, chain approach, include the following patents:
U.S. Pat. No. 3,593,402, issued to Mori on Jul. 20, 1971
U.S. Pat. No. 3,653,574, issued to Dearman on Apr. 4, 1972
U.S. Pat. No. 3,666,159, issued to Watson on May 30, 1972
U.S. Pat. No. 3,704,503, issued to Haywood on Dec. 5, 1972
U.S. Pat. No. 3,705,453, issued to Olson on Dec. 12, 1972
Further examples can be seen in a series of additional patents issued to Dearman:
U.S. Pat. No. 3,901,497, issued Aug. 26, 1975;
U.S. Pat. No. 3,944,202, issued Mar. 16th 1976;
U.S. Pat. No. 3,952,936, issued Apr. 27th 1976;
U.S. Pat. No. 4,586,647, issued May 6, 1986; and
U.S. Pat. No. 4,726,575, issued Feb. 23rd, 1988.
Unaddressed problems have persisted with the chain approach, nevertheless. Slender, threaded shafts, and intermeshing gear means have been attempted, as disclosed by Mori, but slender shafts have a tendency to break under heavy use, and intermeshing gear means can be difficult to adjust, especially when placed close to the workpiece. Attempts have been made to utilize alignment plates permanently joined to the chain, as disclosed in the Olson and Haywood patents, but permanently-joined plates are not adjustable along the chain, for different sizes of pipe. Other attempts have been made to mount alignment devices on the chain using wires, as shown in the Watson ""159 patent, but complications arise from the fragility of the mounting wire, and the lack of bearing area between the chain and the alignment device. The lack of bearing area can lead to rotation and wobble of the alignment device as the chain is tightened.
More recent art for flexible chain clamps is disclosed in the aforementioned Dearman patents, which tend to utilize a combination of jackbars resting on a double or triple chain, the chain held at one end by a pivoting stop, and tightened at the other end by the rotation of a hand crank. Handcranks, however, cannot be fitted in small, congested, or difficult-to-reach workspaces. The jack bars disclosed to date can be complex to make, and easy to abuse and break, due to the number and complexity of their components. The size, weight, and complexity of the various prior-art combinations are ill-adapted for use on non-horizontal workpieces (such as vertical pipe, vertical shafts, or flagpoles), or small size workpieces. A large clamp, and its component crank, can dwarf, or even damage a small workpiece. Excessive lengths of chain can interfere with the operator, particularly in tight spaces. Rotation and wobble of the jackbar can occur during tightening of the chain, due to the gap between the chain and the jackbar, required for movement of the jackbar along the chain.
As alluded to, in the background of the Dearman ""575 patent disclosure, cost, weight, and, by extension, complexity, are important considerations in this art. Overall, the prior art has taught towards greater complexity, and has not addressed the possibility of a slidable alignment of jack bar and chain without nuts, screws, or hand tools to adjust.
The prior art has also focused on pipe, to the exclusion of shapes other than circular pipe cross-sections, and has tended to use chain of rectangular cross section, compromising the stability of the alignment apparatus attached to it. In addition, none of the above prior art has addressed the possibility of aligning more than two workpieces at a time.
Moreover, the prior art, as a whole, has tended to align connecting pipe pieces with sharp-pointed screws or nuts. This can create problems for pipe, fittings, and other workpieces made of titanium or other specialty metals, especially where installed in clean environments, such as food processing facilities, semiconductor assembly buildings, or pharmaceutical plants. Sharp-pointed screws, as used in most of the prior art, can create scratches in the stock or pipe, either causing corrosion in the scratch, or allowing impurities to accumulate in the scratch. Swivel feet could be mounted on the screws or nuts, as disclosed in the later Dearman patents, but would add to the cost and complexity of fabrication.
In summation, pipefitters, plumbers, tradespersons, and others having ordinary skill in the art of joining two workpieces end-to-end, have had an longstanding, ongoing need for compact, light, easy-to-use devices, particularly devices that are sufficiently flexible to use on workpieces of varying cross-sections and sizes, sufficiently durable to withstand rough handling, and sufficiently stable to tightly clamp, without rotation, wobble, or other undesirable movement of the alignment devices. Moreover, the need has persisted for clamps that are simple to fabricate and operate, and quick to set up and break down, with a minimum of parts to manipulate, and a minimum of components to abuse and lose.
A primary object of the present invention is to simply and efficiently align and join a variety of pipe, tube, bar, fittings, and other workpieces, in a variety of sizes and cross-sections, utilizing a minimum of moving parts, a minimum of tightening tools, and a minimum of adjustments.
A related object of the invention is the alignment of workpieces in congested spaces and awkward positions, including spaces and positions where prior art devices have historically not worked well.
A third object of the invention is simplicity and economy of manufacture, using combinations of parts capable of withstanding neglect and abuse, by tradespersons and others.
A fourth object of the invention is ease of use, by operators having a wide variety of aptitude and skill, or, in some cases, having no skill at all.
Additional objects and advantages of the invention will be apparent to those skilled in the art, from the description of the invention contained herein, taken in conjunction with the attached drawings.
In one form of the invention, an clamp assembly includes a flexible member for encompassing the first workpiece, and a means, such as a locking wrench, for securing the flexible member about the first workpiece. One or more connecting workpieces are aligned to the first workpiece, using one or more alignment apparatuses. Each alignment apparatus is made up of an alignment bar assembly, a detent assembly, and at least one adjustable fastener. Each alignment bar assembly bridges the workpieces, and can slide along the flexible member. The alignment bar assembly is, in turn, held in its desired position along the flexible member, by a device such as a spring-loaded detent assembly, which, in this form of the invention, uses a spring to engage a plunger assembly with the flexible member. At least one adjustable fastener, mounted on each alignment bar assembly, exerts an alignment force on each connecting workpiece. Once aligned, the first workpiece can be joined to each successive connecting workpiece, by welding or other means.
Optionally, to prevent damage to the connecting work piece, each adjustable fastener can have a depression, in the area where the adjustable fastener contacts the connecting workpiece, also known as the fastener contact area. Further variations with this feature are possible. The adjustable fastener can have an indentation in its head, to facilitate its tightening and loosening, by a tool or other fitting. The detent assembly, optionally, can have a detent cap. The detent cap, in turn, can have an indentation at its center, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap can also have a hole, to permit lubrication of the detent assembly, while excluding debris. Optionally, for ease of use, the flexible member can have a cruciform cross-section, or be colored according to a range of actual or expected first workpiece cross-sectional perimeters. Also, the plunger assembly can be hardened.
In another form of the invention, a clamp assembly includes the combination of a to flexible member, a lockable tool, and an alignment apparatus. Again, the alignment apparatus is made up of an alignment bar assembly, a detent assembly, and at least one adjustable fastener. The flexible member, in this form, is cruciform in cross-section, with a corresponding cruciform-shaped slot in the alignment bar assembly, to facilitate the sliding of the alignment apparatus on, off, or along the flexible member. A lockable tool is used here to grip and clamp, or grippingly clamp, the flexible member about the first workpiece, and secure it about the first workpiece. The alignment bar assembly contacts the first workpiece, and overlies the connecting workpiece. In this form of the invention, a detent assembly utilizes a spring, to bias a plunger assembly along a detent casing, and through an upper hole in the alignment bar assembly, causing the plunger assembly to engage the flexible member, and restraining the movement of the alignment apparatus along the flexible member. The spring biasing force can be varied, by adjusting the detent cap that restrains the spring. Each connecting workpiece is aligned with the first workpiece, using an adjustable fastener mounted on each alignment bar assembly. Once aligned, the first workpiece can be joined to each successive connecting workpiece, by welding or other means.
Optionally, to prevent damage to the connecting workpiece, each adjustable fastener can have a depression, in the area where-the adjustable fastener contacts the connecting workpiece. The adjustable fastener can have a indentation in the center of its head, or in its center shank, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap, in turn, can have an indentation in its center, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap can also have a hole, to permit lubrication of the detent assembly, while excluding debris. Optionally, the flexible member can be colored according to range of actual or expected first workpiece cross-sectional perimeters, for ease of use. Also, the plunger assembly can be hardened.
In a third form of the invention, an alignment clamp assembly uses a chain, to encompass the first workpiece. The chain is attached to a locking wrench, which secures the chain about the first workpiece. The locking wrench here is removably connected to a connection area of the chain. One or more connecting workpieces are aligned to the first workpiece, using one or more alignment apparatuses. Each alignment apparatus is made up of an alignment bar assembly, a detent assembly, and at least one adjustable fastener. The alignment bar assembly, made up of an upper bar and a lower bar, can be slid on, off, or along the chain, as needed. A wedge-shaped end piece on the free end of the chain, can facilitate the sliding of the alignment bar assembly on or off the free end of the chain. The upper and lower link portions of the chain, and the projecting pivot pins of the chain, define a cruciform cross-section. This cruciform cross-section is matched by the alignment bar assembly, through the use of a slot in the upper bar, mounted on a T-shaped slot in the lower bar. The alignment apparatus is positioned on the chain using a spring-biased detent assembly, positioned inside a hole extending through the upper bar, or, in another form of the invention, positioned atop the upper bar, with a hole to accommodate the projection component of the plunger assembly. The plunger assembly slides within the detent casing, and its spring-biased projection component engages the chain. The spring is restrained by the threaded detent cap, which, in turn, may be rotated along the detent casing, to vary the spring force. One or more connecting workpieces may then be aligned with the first workpiece, and secured with the adjustable fastener mounted on each alignment bar assembly. To prevent damage to the connecting workpiece, each adjustable fastener has a depression, in the area where the adjustable fastener contacts the connecting workpiece. Once aligned, the first workpiece can be joined to each successive connecting workpiece, by welding or other means.
Optionally, the adjustable fastener can have a head indentation in its center, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap, in turn, can have a cap indentation in its center, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap can also have a hole, to permit lubrication of the detent assembly, while excluding debris. Optionally, the hole can be sized to not be more than approximately 1 mm (0.04 in.) in diameter. Optionally, the chain can be colored according to a range of actual or expected first workpiece cross-sectional perimeters. Also, the plunger assembly can be hardened, or can have a spring seat, to restrain lateral movement of the spring.
Subcombinations of the Alignment Clamp Assembly
Separate forms of the invention focus on the subcombination of the alignment bar assembly, the detent assembly, and the adjustable fastener, which, together, make up the alignment clamp apparatus.
In one such form, the alignment bar assembly of the alignment apparatus utilizes an upper bar having an upper slot and an upper bar hole, and a lower bar with a T-shaped groove. The upper slot and the T-shaped groove are aligned, to slidably engage a flexible member encompassing the first workpiece. In this form of the invention, the detent assembly includes a spring-biased plunger assembly and a detent cap, with a spring-biased projection into the upper slot, through the upper bar hole. The spring-biased projection engages the flexible member, while the detent cap restrains the spring, and adjusts the amount of spring force. One or more connecting workpieces may then be aligned with the first workpiece, and secured using the adjustable fastener mounted on each alignment bar assembly. Once aligned, the first workpiece can be joined to each successive connecting workpiece, by welding or other means.
Optionally, to prevent damage to the connecting workpiece, the adjustable fastener, in this form of the invention, can have a depression, where it contacts the connecting workpiece. The adjustable fastener can have a indentation in its head, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap, in turn, can have a cap indentation, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap can also have a hole of not more than approximately 1 mm in diameter, to permit lubrication of the detent assembly, while excluding debris. Optionally, the plunger assembly can be hardened. Also, a spring seat can be provided on the plunger assembly, to restrain the lower end of the spring.
In another form of the invention subcombination, the alignment apparatus utilizes the same combination of alignment bar assembly, detent assembly, and adjustable fastener, to slidably engage a chain encompassing the first workpiece. The alignment apparatus slidably engages the chain using an upper bar and a lower bar, more particularly, an upper slot in the upper bar, and a lower slot and lower groove, in the lower bar. A spring-loaded detent assembly is situated within the upper bar or, in another form of the invention, on the upper bar. In either form of the invention, the detent assembly includes a detent casing, and a plunger assembly. In the first case, an upper bar hole is sized to accommodate the entire detent assembly. In the latter case, the upper bar hole is sized to slidably accommodate a projection of the plunger assembly. The spring-biased plunger assembly engages the chain, while the detent cap restrains the spring, and can be used to adjust the amount of spring force. Optionally, for these two forms of the invention, a spring seat may be provided on the plunger assembly. As before, one or more connecting workpieces may then be aligned with the first workpiece, and secured using the adjustable fastener mounted on each alignment bar assembly. The adjustable fastener, in these two forms of the invention, has a depression, where it contacts the connecting workpiece, to prevent damage to the connecting workpiece. Once aligned, the first workpiece can be joined to each successive connecting workpiece, by welding or other means.
Optionally, the adjustable fastener can have a indentation in its head, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap, in turn, can have an indentation, to facilitate its tightening and loosening, by a tool or other fitting. The detent cap can also have a hole of not more than approximately 1 mm in diameter, to permit lubrication of the detent assembly, while excluding debris. Optionally, the plunger assembly can be hardened. Also, a spring seat can be provided on the plunger assembly, to restrain the lower end of the spring.
Process and Method Forms
In addition to the above forms of the invention, another form of the invention may be defined, by the process used to make the alignment apparatus. An upper hole is bored in an upper bar, and a detent casing is inserted into the upper bar. The detent casing is partially threaded. An upper slot is milled in both the upper bar""s lower surface, and in the detent casing. In another form of the process, the detent casing may be mounted on the upper bar, about the upper bar hole, and the upper slot is milled in the upper bar only. An overlying portion is milled, and a fastener hole is bored and threaded, in the lower bar. In addition, a lower slot and a lower groove are milled in the upper surface of the lower bar. The upper bar is mounted on the lower bar, so that the upper slot, lower slot, and lower groove will slidably accommodate a flexible member. A plunger assembly, then a spring, is inserted into the detent casing, so that its projection will engage the flexible member. A detent cap is threaded into the detent casing, to restrain the spring, and a threaded fastener is installed into the fastener hole.
Optionally, the plunger assembly may be hardened, and a cap hole, not exceeding approximately 1 mm in diameter, may be bored into the detent cap.
An additional form of the invention is disclosed through the process of color-coding a chain corresponding to a range of perimeters expected for the first workpiece. The chain is attached to a locking wrench. One or more alignment apparatuses are slid onto the chain, and the chain, with the alignment apparatuses, are mounted about the first workpiece. Each alignment apparatus is positioned about-that portion of the chain encompassing the first workpiece, and the locking wrench is locked. One or more connecting workpieces are aligned with the first workpiece, using an adjustable fastener on each alignment apparatus. The connecting workpieces are joined to the first workpiece; the locking wrench is unlocked; and the chain is released from the locking wrench, and unmounted from the first workpiece.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description, taken in conjunction with the accompanying drawings, and its scope will be pointed out in the appended claims.